Looking for some post clutch install help

BACKGROUND:
Just installed clutchmaster stage 3 clutch (still in the burn in period), and ZZP front trans mount. Adjusted shifter cables and car seems to be about back to normal in terms of shifting gears/getting into reverse, etc. Still getting used to the engagement right off the clutch floor but it’s not too bad (may need to clutch bleed).

PROBLEM:
Noticed that after clutch job, when shifting under load, typically 2nd to 3rd, I get this steering wheel shake/shimmy when disengaging say 2nd gear and again when reengaging in 3rd gear.

MORE INFO:
Doesn’t happen when I have a very limited load such as shifting from 3rd to 4th @40ish mph. When I removed the subframe, I noticed the lower cabs were a bit chewed and order a new set. But I wasn’t having this issue before I did the clutch. Also haven’t gotten an alignment yet bc I did an alignment just 1 week before doing clutch bc I got all new tires.

Anyone had exp. with this before? Steering wheel/torque shake/shimmy when changing gears under load? Or any idea what it might be?

VEHICLE:
2010 Chevrolet Cobalt SS
Approx. 77k miles
Completely stock minus:
ZZP CAI
drilled and slotted rotors.

Any help is appreciated!
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